31st may round silver object flew over waltham abbey area for around 2-3mins then slowly blended into the clear sky ahead

it was a clear sunny suday afternoon and was watching this plane from my window when this disc appeared, i shouted to my wife and children to have a look? my wife said it must be a plane? but this had no (back stream) we live near three airports and we see planes at various hights and you know a plane when you see it.what i seen was posssily the bottom of the object with the sun shining on it or the bottom with the glare (flare)from the engine? it cut across the sky not much faster than a plane but it was enough to blend into the horizon within 2-3mins.